Typically, an internal combustion engine has a fill opening for adding oil to the engine crankcase. Over time, contaminated air accumulates in the crankcase and needs to be relieved.
In accordance with the present invention, the oil fill is in the form of a pipe including a vent for releasing air from the crankcase. A fluid carrying conduit leads from the air vent to the air intake of the engine. Specifically, a negative pressure created by air intake into an operating engine can be used to draw air and oil vapors from the engine's crankcase. At the same time that air and oil vapor is withdrawn, there is a potential to draw and oil mist and products of combustion out of the engine. A baffle in the fill pipe intercepts this oil mist and products of combustion intermixed with the air prior to being vented into the air intake of the operating engine. Also, a positive crankcase ventilation (PCV) valve in the air vent prevents reverse flow of air as well as regulating the flow rate.
More particularly, the upper end of the oil fill assembly preferably has an enlarged mouth so as to provide a convenient inlet for the introduction of oil into the assembly. The enlarged mouth serves as a funnel to facilitate the oil filling operation.
The oil mist baffle is preferably releasably secured in the fill pipe. The releasable security mechanism includes a catch portion in the fill pipe and a clip potion on the baffle which is releasably engagable with the catch portion. The clip is preferably an elongated member integrally extending form the main body of the baffle and with a free end having a hook configuration engagable over an abutment surface of the catch with a snap-like action.
One object of this invention is to provide an oil fill assembly including a pipe portion and an air vent system having the foregoing features and capabilities.
Another object is to provide an oil fill pipe combined with an air vent system constructed of few simple parts, is rugged and durable in use, and is capable of being inexpensively manufactured and assembled.
These and other objects, features and advantages of the invention will become more apparent as the following description proceeds, especially when considered with the accompanying drawings.